Your connection scheme is unusual. Most tvs do not have a sub out. Sub is kicked on in response to low frequency signal from amp/receiver. How low depends on crossover setting and other factors. Detail your set up.
i'm sorry I must have mixed my words. What I meant was I have a normal analog signal going to my TV and then from the TV to the receiver. My sub doesnt recongnize a signal when i'm watching TV all the time. Why is this and what causes the sub to kick on. Sorry for the mix up.
Could be any number of reasons including crossover and volume settings, tvs inability to convey low frequency info or lack of low frequency info in certain programming.
I have a MERAK MS-885 SUbWOOFER that lately stopped responding to the signal coming from my pioneer amp. The unit powers up when it does receive the signal but never produces and sound. I have checked all the connections and can get an audible hum (feedback) when I cross over the wires. I checked the fuse in the subwoofer and looked for any loose wires. Still nothing. Any suggestions ? Does anyone know where I can get a wiring schematic for this unit ?